This invention relates to an apparatus for providing means for re-charging and re-sealing a hollow toner hopper, which is a component of an expensive toner cartridge assembly, used in a dry toner printer, copying machine, or facsimile
machine, which will permit the hopper, re-charged with dry toner, and shipped from one location to another, to avoid spilling the dry toner powder (which behaves similar to a liquid).
It has been the practice for a manufacturer of printers, copying machines, and facsimile machines to fill the toner hopper, located in the toner cartridge assembly, with dry toner, and seal closed the top of the toner hopper with a plastic sheet, attached to, and sealed on both sides and ends of the hopper, prior to assembling the toner hopper with the other components of the toner cartridge. When the toner cartridge assembly is received at the user's location, the seal is removed from the cartridge, and the printer, copier, or facsimile machine is ready for use, with the toner being exposed to the feed roller device for making copies.
Recent developments in the dry toner imaging industry have led to the use of "throw-away" type toner cartridge assemblies, whereby the user of the copier or printer must buy a new, toner cartridge assembly from the manufacturer when the original toner cartridge assembly is depleted of toner. This method of throw-away toner cartridges is very expensive to a user of the copier, facsimile machine, or printer since a new cartridge is required each time the toner hopper is depleted. The toner is expensive enough, but to add the expense of a new cartridge assembly, with its toner dispensing means, adds a substantial amount to the cost of maintenance.
It has been customary in the past to throw away these very expensive, empty toner cartridge assemblies, and replace them with new, filled, and sealed factory toner cartridge assemblies. The manufacturers seal the toner hopper components in these new toner cartridge assemblies at their manufacturing location, and there is no leakage of the toner during shipment. This type of operation, using expensive throw-away, cartridge assemblies, has led to the need for a method and apparatus for re-charging, re-sealing, shipping, and re-using these toner cartridge assemblies, with the obvious savings of the cost of the new toner cartridge assembly, and all its components, in addition to the benefits of avoiding disposal and the environmental problems created thereby.
No prior art is available for comparison to this invention, although the inventor is aware of several developments which have attempted to solve the problem and several references are cited, in applicant's earlier application Ser. No. 845,722, filed Mar. 4, 1992, which outlines the problem of dry toner usage in printers, copiers, and facsimile machines. Thus, it is obvious to a prior user of these printers and copiers that any leakage from the toner cartridge assembly creates a major cleaning problem at best, and may cause severe soiling, costly damage to the surrounding environment, in the normal accident, as well as damage to the equipment.
One such product for re-charging the dry toner hopper assembly when re-charging, uses a plastic sheet, which slides into a slot in the toner hopper section of the toner cartridge, created when the original seal has been removed.
Another product for re-sealing the dry toner in the re-charged hopper uses a plastic sheet with a magnetic coating, to try to keep the dry toner from spilling during shipment to the user. Still others try to duplicate the factory method which may require disassembly and modification of the toner hopper and thorough cleaning of the seal-grooves.
Most of the prior products, for sealing the dry toner hopper for shipment, have a major design problem. This problem centers around the long slots along the longitudinal surface of the dry toner hopper. These slots are not properly sealed along this longitudinal axis, once the original seal has been removed, leaving irregular openings along the longitudinal axis. It will be noted that the prior products of a fixed thickness slide into the uneven slot, to fill only parts of the slot length, leaving minute openings along the longitudinal axis of the toner hopper, with the resulting leakage of toner during shipment, causing major problems to both the shipper, and the receiver of the re-charged dry toner hoppers.
Another problem involves some toner hoppers that have a very narrow slot constriction that the toner seal, wider than the slot, must pull through. It is very cumbersome to seal such a toner hopper with a narrow slot constriction because the seal's width must pull through the constriction.
Another problem involves seal re-usability. In the prior art, those seal systems that are re-usable tend to leak, while those that do not leak are not re-usable. Those seal systems that use a form of sticky back tape alone as the seal, have four general problems. First, these seals may tear. Second, they may stick to toner in the slot causing them to unstick during use, not forming a perfect seal. Prevention of this requires an excessive amount of extra labor in cleaning toner from the seal-grooves each time the cartridge assembly is recharged. Third, these seal systems do not consistently seal well. A fourth problem involves foam-tearing. Many such seals that are leakproof tear the sealing foam in the hopper. The sticky tape tears the foam, then the sealing foam tears from use of the common metallic insertion tool on each usage cycle. Once this foam partially tears out, the hopper will then leak, causing the problem the seal was supposed to prevent.
One such seal of prior art, U.S. Pat. No. 5,080,745 is similar in that it uses an insertion tool to fix the removable closure seal to the hopper assembly. However, this prior patent does not disclose the use of a slotted seal insert.
Another problem with prior art is that those seals that are leakproof tend to take a substantial length of time to install, unlike the slide-in closure seal means of this invention. Those contemporary seals that are slide-seals, of the prior art, tend to leak.